七氟烷通过P^(70S6K)/Nrf2信号通路诱导神经元HO-1mRNA表达

Sevoflurane induces neuron HO-1 mRNA expression via P^(70S6K)/Nrf2 kinase signal pathways

目的探讨七氟烷(Sevoflurane)诱导神经元血红素氧合酶-1(HO-1)基因表达的信号转导通路。方法将培养7d的新生大鼠海马神经元随机分为4组:正常培养组(C组)、2%七氟烷组(S1组)、4%七氟烷组(S2组)和4%七氟烷+Rapamycin组(R组)。C组神经元按正常培养方法培养。S1组和S2组神经元分别给予2%或4%七氟烷处理60min后继续培养24h。R组在神经元给予4%七氟烷处理同时在培养液中加入Rapamycin使其终浓度为10nmol.L-1后同S2组处理。收集神经元进行HO-1mRNA和P70S6K、Nrf2、AP-1和HO-1蛋白表达的检测。结果S1组P70S6K和Nrf2蛋白表达增加(vsC组,P<0.01),HO-1mRNA和HO-1蛋白表达增加(vsC组,P<0.01),AP-1蛋白表达变化不明显(vsC组,P>0.05)。S2组P70S6K和Nrf2蛋白表达增加(vsS1组,P<0.05),HO-1mRNA和HO-1蛋白表达增加(vsS1组,P<0.05),AP-1蛋白表达变化不明显(vsS1组,P>0.05)。R组P70S6K和Nrf2蛋白表达减少(vsS2组,P<0.01),HO-1mRNA和HO-1蛋白表达减少(vsS2组,P<0.01),AP-1蛋白表达变化不明显(vsS2组,P>0.05)。结论Sevoflurane通过P70S6K/Nrf2信号通路诱导神经元HO-1mRNA表达。

Aim To investigate signal pathway associated with sevoflurane-indueed neuron hemeoxygenase-1 （ HO-1 ） expression. Methods Newborn （24 - 48 h） Wistar rats were decapitated and hippocampus tissue was digested with 0. 125% trypsin,and suspended in a medium containing DMEM supplemented to 25 mmol· L^-1 glucose,10% fetal bovine serum, 10% horse serum, and 2 mmol · L^- 1 glutamine. Cells were plated at 1.0 × 10^6 · L^- 1 on poly-Dlysine-treated 6-well （2 ml/ well） plates and were treated with 10 μmol · L^-1 cytosine arabinoside on day 4 to minimize glial growth. One-half of the medium was replaced twice a week with medium consisting of DMEM （4.5 g ~ L-~ glucose）/ F12（1 ： 1）,5% fetal bovine serum and 5% horse ser- um. Cells were used after growing for 7 days. Cells were randomly divided into 4 groups： control group （C group）, 2% Sevoflurane group （S1 group ）, 4% Sevoflurane group （S2 group ） and 4% Sevoflurane ＋ Rapamycin group （R group ）. Control cells were cul- tured normally. Group S1 and S2 cells were precondi- tioned with 2% or 4% Sevoflurane, then cultured normally for 24 hours. Group R cells culture medium was added with 10 nmol · L^-1 Rapamycin and precondi- tioned with 4% Sevoflurane,then cultured normally for 24 hours. The expression of HO-1 mRNA, P^70S6K, Nrf2, AP-1 and HO-1 protein was detected. Results 2% Sevoflurane enhanced neuron expression of P^70S6K and Nrf2（vs group C,P 〈0. 01 ）,and increased neuron ex- pression of HO-1 mRNA and HO-1 （vs group C, P 〈 0.01 ）. 4% Sevoflurane enhanced neuron expression of P^70S6K and Nrf2 （ vs group S1, P 〈 0.05 ） , and increased neuron expression of HO-1 mRNA and HO-1 （vs group S1 ,P 〈0. 05）. Rapamycin inhibited neuron expression of P^70S6K and Nrf2（vs group S2,P 〈0. 01 ） ,and inhibited neuron expression of HO-1 mRNA and HO-1 （vs group S2 ,P 〈 0. 01 ）. There was no difference of AP-1 protein expression had in each group. Conclusion Sevoflurane induces neuron HO-1 mRNA expression via P^70S6K/Nrf2 kinase signal pathways.